1. Field of the Invention
This invention relates to rubber compositions and to hoses having such compositions incorporated.
2. Prior Art
There have arisen various problems in bonding rubbers of different formulations as well as in bonding rubbers with such metallic and fibrous materials as commonly employed to reinforce rubber products. Cements, and rubber-based compositions in particular are widely used as adhesives for such bonding.
A variety of rubber-based compositions have been proposed to bond rubbers to brass and to organic fiber cords treated with a blend of a resorcin-formalin condensate and a latex (hereinafter referred to as "RFL") and also to other different rubbers. One such composition has sulfur added in large amounts. Another composition is known in which is introduced a silica-resorcin donor-methylene donor component, also simply called "HRH". The resorcin donor here used is resorcin or a resorcin-formalin condensate, whereas the methylene donor is usually hexamethylenetetramine. A further prior art composition involves the use of a mercaptotriazine compound.
However, the sulfur-rich and HRH-containing adhesives are encountered with insufficient adhesion, hence reduced resistance to water, when applied to the bonding of rubbers with brass, RFL treated organic fiber cords or other rubbers. The mercaptotriazine-based adhesive forms a strong, water-resistant bond in rubber-to-brass bonding, but has been found totally unsatisfactory both in rubber-to-RFL treated fiber cord bonding and in rubber-to-rubber bonding. This has created an urgent need for improved rubber-based compositions which are capable of imparting strong adhesion to such metallic, fibrous and rubbery materials.